The present disclosure generally relates to energy conservation in a building. The present disclosure relates more specifically to detecting changes in the energy use of a building (e.g., energy usage by HVAC equipment).
In many areas of the country, electrical generation and transmission assets have or are reaching full capacity. One of the most cost effective ways to ensure reliable power delivery is to reduce demand (MW) by reducing energy consumption (MWh). Because commercial buildings consume a good portion of the generated electricity in the United States, a major strategy for solving energy grid problems is to implement energy conservation measures (ECMs) within buildings. Further, companies that purchase energy are working to reduce their energy costs by implementing ECMs within buildings.
Entities that invest in ECMs typically want to verify that the expected energy savings associated with ECMs are actually realized (e.g., for verifying the accuracy of return-on-investment calculations). Federal, state, or utility based incentives may also be offered to encourage implementation of ECMs. These programs will have verification requirements. Further, some contracts between ECM providers (e.g., a company selling energy-efficient equipment) and ECM purchasers (e.g., a business seeking lower ongoing energy costs) establish relationships whereby the ECM provider is financially responsible for energy or cost savings shortfalls after purchase of the ECM. Accordingly, Applicants have identified a need for systems and methods for measuring and verifying energy savings and peak demand reductions in buildings. Applicants have further identified a need for systems and methods that automatically measure and verify energy savings and peak demand reductions in buildings.
Once a baseline model has been developed for measuring and verifying energy savings in a building, the baseline model may be used to estimate the amount of energy that would have been used by the building if ECMs were not performed. Calculation of the energy avoidance may be rather simple if the baseline model is accurate and routine adjustments related to building usage are included in the baseline model. However, non-routine adjustments related to building usage may not be included in the baseline model, and therefore not included in the energy avoidance calculation. Examples of static factors for which non-routine adjustments may occur include the size of the facility, the hours of operation of the building, the number of employees using the building, the number of computer servers in the building, etc.
Such non-routine adjustments may cause problems during the reporting period when trying to verify energy savings in a building. An unnoticed change (e.g., a non-routing adjustment) in static factors may cause energy savings in the building to be underestimated. This may cause an engineer to miss requirements in a contract or cause a building owner not to invest money in ECMs even though the actual return on investment was high.
Unaccounted for changes in static factors that occur during the baseline period may also negatively impact calculations (e.g., creation of an accurate baseline model). If changes in static factors occur during the baseline period, the statistical regression module used to build the baseline model may essentially be based on a midpoint between energy usage before the change in static factors and energy usage after the change in static factors. Such a situation may lead to an inaccurate estimation of energy usage. For example, if a change in static factors causes a decrease in energy usage, the energy savings of the building due to the ECMs will be overestimated by the baseline model, and the building owner may be disappointed with a resulting return on investment. As another example, if a change in static factors causes an increase in energy usage, the energy savings of the building will be underestimated by the baseline model, and a performance contractor may miss the contractual guarantee of energy savings and be required to reimburse the building owner. Monitoring static factors traditionally requires manual monitoring. This may lead to changes in static factors going unnoticed or incorrectly calculated.